This invention relates to multi-cell tiles which are used in the heat and mass transfer section of a liquid cooling tower, and, more particularly, to tiles which are provided with openings for increasing the heat and mass transfer which is provided by the tiles.
Cooling towers are used to cool liquid by contact with air. The liquid is allowed to flow downwardly through the tower, and a countercurrent flow of air is drawn through the falling liquid by various means. A common application of liquid cooling towers is for cooling water (dissipating waste heat) used in electrical generating and process plants and industrial and institutional air conditioning systems.
One type of prior art cooling tower utilizes stacked layers of clay tiles. The tiles are formed by extruding clay to form a tube having a generally rectangular cross-section and a plurality of axially extending cells. The extruded tube is transversely severed by cutting wires to form individual tiles having an axial length of about five to eight inches (12.7 to 20.3 cm.). The rectangular tiles may have transverse dimensions of about 9 to 10 inches (22.9 to 25.4 cm.) and two to five cells on each side. Thereafter the tiles are hardburned to form a hard, structural tile. The tiles are stacked in layers so that the cells of the tiles extend vertically. The tiles of each layer are stacked directly on the tiles of the previous layer, and the tiles of each layer are preferably offset so that the cells of one tile are not vertically aligned with the cells of the tiles above and below. The tiles within each layer are spaced laterally from adjacent tiles of the same layer.
The tiles are stacked within a confining wall, and the water or other liquid to be cooled is introduced to the top of the stack by, for example, spray nozzles. The water flows downwardly over the walls and through the cells of the tiles and through the spaces between adjacent tiles of the same layer. Air flow is induced upwardly through the stack countercurrently to the water. The air helps to break the water into droplets, and the contact between the air and the water results in heat and mass transfer from the water to the air.
U.S. Pat. No. 4,382,046 describes an improved cooling tower in which spacers are inserted between adjacent layers of tiles. The spacers create a vertical space of from one to four inches (2.5 to 10.2 cm.) between the layers of tile, and air and water can therefore flow transversely to some extent between adjacent layers. The pressure drop or the resistance of air flow through the stack is thereby reduced. The use of layers of spacers also results in better heat and mass transfer between the water and the liquid. The spaced layers therefore enable the required air to be induced with less energy while increasing the transfer efficiency of the cooling tower or enable the size of the cooling tower to be decreased without decreasing the cooling capacity.